Located in Uruguay, comprises the whole of the republic. This territory was under the jurisdiction of the Paraguayan Church till 1620, when it became subject to Buenos Aires. In 1828 the Holy See erected it into a vicariate Apostolic. On 15 July, 1878, it was raised to episcopal rank, Mgr. Hyacinth Vera being first bishop; on 19 April, 1897, it was made an archdiocese. It was decided at that time to erect two suffragan sees, Melo and Saltó, but no appointments have yet been made (1910). Since colonial days ended, the Church has been persecuted at times, especially between 1880 and 1890 under Santos, who forbade religious under forty to make vows, instituted civil marriage, and made it a crime to baptise a child before its birth was registered civilly. To-day, however, the Church is flourishing, and the archdiocese contains many congregations of men (Jesuits, Capuchins, Redemptorists, Salesians, etc.), and over 300 nuns engaged in teaching and charitable work. The diocese contains 72,210 square miles, and about 1,103,000 inhabitants (in 1906), almost all Catholics, of whom 308,000 were in the Department of Montevideo. There are 46 parishes, 7 filial cures, 122 priests, and about 100 chapels and churches. The present occupant of the see is Mgr. Mariano Soler, born at San Carlo, Uruguay, 25 March, 1846; elected bishop, 29 June, 1891; consecrated archbishop, 19 April, 1897; he has two auxiliary bishops: Mgr. Ricardo Isasa (titular Bishop of Anemurium), born at Montevideo, 7 February, 1847; elected, 15 February, 1891; and Mgr. Pio Gaetano Secondo Stella (titular Bishop of Amizona), born at Paso del Molino, Uruguay, 7 August, 1857; elected, 22 December, 1893. Almost all the inhabitants are Catholics, there is, however, a small Piedmontese Waldensian agricultural colony in the East of Colonia.

Among the noteworthy buildings of the City of Montevideo may be mentioned the cathedral, begun in 1803, completed and restored in 1905; and the Jesuit, Redemptorist, and Franciscan churches. Within recent years conferences of St. Vincent de Paul have been established in all the city parishes; likewise an excellent Catholic club; and an institute for Catholic working-men. The city dates back to early in the seventeenth century; a small fort, San José, was built there in 1724; in January, 1728, the town was founded by Bruno de Zabala with the name San Felipe y Santiago; in 1807 it was captured by the British; in 1828 it became the capital of the republic; from 1842 to 1851 it withstood the nine years' siege by Oribe and his Argentine allies. Montevideo has within recent years grown to be one of the seven greatest seaports in the world (see URUGUAY). San José de Mayo (9000) contains a magnificent church, more massive than the cathedral; and also the college of the Sisters of Nuestra Señora del Huerto, which has a very pretty chapel attached. (For the early Uruguayan missions among the Indians see REDUCTIONS OF PARAGUAY.)